Sieve drum device for the bonding and strengthening of felt and similar products

ABSTRACT

An improved sieve drum device for bonding of textile material containing thermoplastic binder fibers which become tacky or melt upon the application of heat, which comprises a first sieve drum means subjected to a suction draft and rotatably mounted in a housing for heating the textile material, rolls located at the outlet of the housing for applying pressure to the textile material, and a second sieve drum means for cooling of the textile material, the first sieve drum means being operatively associated with means for providing a fresh air intake opening adjacent to the rolls.

United States Patent [191 Fleissner Dec. 30, 1975 SIEVE DRUM DEVICE FORTHE BONDING AND STRENGTHENING 0F FELT AND SIMILAR PRODUCTS [75]Inventor: Heinz Fleissner, Egelsbach near Frankfurt am Main, Germany[73] Assignee: Vepa Aktiengesellschaft, Switzerland [22] Filed: Feb. 20,1973 [21] Appl. No.: 333,734

[30] Foreign Application Priority Data Feb. 19, 1972 Germany 2207896[52] U.S. Cl. 34/115; 68/DIG. 5; 156/381; 156/498; 156/499; 425/83 [51]Int. Cl. B291) 7/00; F26B 11/04 [58] Field of Search 156/622, 282, 285,311, 156/380, 381, 497-499, 62.4; 34/10, 111,

115 X, 116;68/5 R,5 A,5 B,5 C,5 D,5 E,

DIG. 5, 8; 425/83, 80, 81

3,445,947 5/1969 Fleissner 34/115 3,490,115 1/1970 Owens et al. 156/6223,512,265 5/1970 Fleissner 34/10 3,585,729 6/1971 F1eissner.... 34/1153,615,962 10/1971 Kaspar 156/622 3,619,322 11/1971 Fleissner 156/282Primary Examiner-Douglas .1. Drummond Assistant Examiner-M. G. WityshynAttorney, Agent, or FirmCraig & Antonelli [5 7] ABSTRACT An improvedsieve drum device for bonding of textile material containingthermoplastic binder fibers which become tacky or melt upon theapplication of heat, which comprises a first sieve dlrum means subjectedto a suction draft and rotatably mounted in a housing for heating thetextile material, rolls located at the outlet of the housing forapplying pressure to the textile material, and a second sieve drum meansfor cooling of the textile material, the first sieve drum means beingoperatively associated with means for providing a fresh air intakeopening adjacent to the rolls.

9 Claims, 1 Drawing Figure U.S. Patent Dec. 30, 1975 SIEVE DRUM DEVICEFOR THE BONDING AND STRENGTHENING OF FELT AND SIMILAR PRODUCTS Thisinvention relates to an improved sieve drum device and process for thebonding and strengthening of fleece, stitched or needled felts, felt andsimilar products by means of thermoplastic binder fibers contained inthe fleece, which are made to become tacky or to melt by a shock-likeheat treatment. More particularly, this invention relates to animprovement in the sieve drum device comprising a housing with a firstsieve drum subjected to a suction draft and rotatably disposed thereinfor the heat treatment of the textile material, followed by a pair ofrolls, which are associated with a second sieve drum unit subjected to asuction draft for cooling, e.g. fixation or setting, of the felt,disclosed in US. Pat. No. 3,619,322.

The use of fusible fiber bonding has been well-proven in practice. Thenonwoven textiles obtained in this manner are capable of exhibiting auniform strength over their cross section, due to the thoroughintermixing of the textile material to be bonded with the fusiblefibers. The process disclosed in the heretofore described U.S. patentproposes to effect the treatment of such nonwoven fabrics interspersedwith fusible fibers with the aid of the throughflow principle (i.e. withsieve drum means), since in this way the immediate heating of thematerial to the treatment temperature is possible simultaneously overthe entire cross section. This also ensues in a uniform bonding over thecross section.

US. Pat. No. 3,619,322 suggests, for the treatment of the material bymeans of throughflow principle, an apparatus consisting of a sieve drumunit for heating the textile material containing synthetic bondingfibers, a leveling or conditioning device, and a sieve drum unit forcooling the textile material. This series of units proved to be mostappropriate. However, such apparatus requires special constructionaldesigns which renders it usable specifically for this application.

The essential requirement to be met by such an apparatus is not only thepossibility of treating a certain product of a specific composition at apredetermined delivery speed, but, rather, also the possibility ofbonding on such an apparatus all other imaginable nonwoven fabrics withfusible fibers (or bonding fibers) contained therein, namely, forexample, products having a smooth structure on both surfaces, as well asthe socalled textured material which exhibits at least on one surface aparticularly voluminous surface texture. However, if such a material ispressed on the fabric face, for example, by the above-mentioned levelingdevice, the voluminous surface texture becomes flat, which, of course,is undesirable.

Starting with the apparatus according to the US. Pat. No. 3,619,322,this invention has for its objective the provision of a sieve drumdevice which makes it possible, in its individual constructionaldetails, to conduct an optimum treatment of all possible nonwovenfabrics with binder or fusible fibers contained therein. Thus, thedevice is to be universally applicalbe to this field of nonwovenapplication.

The device of this invention is characterized in that the pair ofcooling rolls is disposed directly at the outlet of the first sieve drumhousing; the rolls are pressed against each other at a variablepressure, for example, hydraulically or pneumatically; and the sievedrum is 2 associated, across its operating width in the zone covered bythe textile material to be treated and in the zone of the pair ofcooling rolls, with a fresh air intake opening which is preferablyadjustable in its opening cross section, i.e., the size of the openingis controlled.

By means of a sieve drum heating device constructed in this manner, anyimaginable type of bondable textile material can be treated in thedesired way without the danger of inappropriate treatment.

For example, if it is intended to produce lining fabrics, cleaning rags,or the like, wherein a thorough bonding, a uniform fusion of the fibersover the cross section, and a homogeneous smoothness of both surfacesare desirable, the pair of pressure rolls, the rolls of which preferablyrotate in a driven manner and are optionally even coated with Teflon,will exert increased pressure on the material. A firm, uniformly strongproduct is the result of such treatment. However, if it is intended topass a textured material through the machine, the face of which is, ofcourse, not in contact with the surface of the sieve drum, this materialmust not travel through the pair of pressure rolls, since otherwise thedesired texture on one surface would be lost. In this instance, by meansof the otherwise closed-off fresh air intake opening at the outlet end,cold air is applied by the suction draft of the fan to the materialexiting from the sieve drum; consequently, the textile material is atleast partially set or fixed prior to contacting a roll of the pair ofpressure rolls, and even guide rolls do not leave impressions any moreon the textile material. In this connection, it is advantageous to movethe pressure rolls apart, for example, by lifting the upper roll by aspring force and pressing the upper roll downwardly against the springforce by pneumatic or hydraulic means. Of course, the drive, i.e., themechanism for rotating the roll, of this lifted roll should bedisengaged during this lifting step.

If it is intended to bond textile material to be leveled by the pair ofpressure rolls on the machine, then fresh air must also be continuouslyfed to the treatment atmosphere during this process. Since, in thiscase, the fresh air intake opening at the: material outlet is to beclosed, a further development of the apparatus of this inventionprovides a further air intake opening at the inlet of the apparatus, inaddition to the opening at the outlet, the opening cross section of thisfurther opening being likewise preferably adjustable and sealable.

Thus, the fresh air can be conducted, as desired, through one of the twoopenings or also through both openings into the sieve drum heatingdevice or unit. By means of the respectively opened cross sections ofthese openings, the amount of the treatment gases discharged from theconventional air exhaust of the device is likewise controlled.

In addition to the aforementioned possibility for adjusting the devicein dependence on the textile material to be treated, the device shouldalso be adjustable with respect to the respective feeding speed of thetextile material. However, such a device can only be equipped with asieve drum of a certain diameter which is not variable. By varying thefeeding speed, the treatment period is necessarily likewise changed,which must be avoided for obtaining a constantly uniform, high-qualityproduct. The device according to this invention is usable universallyalso in this respect, by providing, for example, that the fan isvariable (i.e. the fan can be adjusted) in its output (i.e., the suctiondraft applied to the sieve drum), for instance by means of a slip-ring 3rotor engine, by means of-a d.c. motor, or a proportional variabletransmission drive.

A further, optionally more satisfactory measure for obtaining the sameeffect in the control of the suction draft is the provision of avariable internal cover which is to be arranged in addition to thecustomary cover in the area of the sieve drum not covered by thematerial. This additional internal cover serves to shield, as desired, aportion of the periphery of the sieve drum covered by the materialagainst the suction draft in the inlet zone of the device, so that theeffective treatment surface of the sieve drum is reduced. In otherwords, the peripheral surface of the drum through which the treatmentmedium passes is reduced. Also, this additional inner cover can be madeto be air-permeable, eg it can be perforated or provided with louvers.This feature can also effect an adjustment of the effective treatmenttime and the magnitude of the suction draft.

Textile materials of the aforementioned bondable type which areuniformly provided with binder or fusible fibers over the entire crosssection have an appearance on their faces which only slightly resemblesa textile material. In many cases, the products have an undesirably hardsurface. As a remedy, the above-mentioned textured material wasdeveloped which, however, is expensive in its manufacture. The sameholds true for a layered material. This disadvantage can be eliminatedby a remarkably unique and simple improvement of the sieve drum device,and a product can be obtained thereby which has maximum textileproperties and thus is uniformly interspersed with binder fibers. Theimprovement to the sieve drum device consists in providing, in the zonebetween the first and the second sieve drums, a heating unit whichsubjects preferably the backside of the material to a high-energyradiation, for example, an infrared heating device. By heating thematerial on the first sieve drum to up to about -l5C. below the bondingtemperature of this material, and then effecting an additional heatingstep with the aid of the infrared heating device (which should heat thematerial only on one side, namely, on the backside, up to the bondingtemperature) then the material, after being cooled on the second sievedrum, will have the above-mentioned disadvantageous feel or handle onlyon the backside, while the desired textured character is obtained on theface side, which need not be heated to the bonding temperature.

By means of the above construction, the sieve drum device can be adaptedas desired to the product to be treated in each individual case, withoutaltering the external design of the device. It is possible to bond onthis device textured material, as well as smooth material, e.g. liningfleeces, cleaning rags, and the like; considering the delivery speedprovided by the units connected in front of the sieve drum device, thetreatment time can be kept constant or it can be varied.

The drawing shows schematically an embodiment of the device of thepresent invention.

A textile treating plant consists of a fleece laying device 1, aneedling machine 2 which receives the fleece 3, fed by the laying device1 to be needled therein, a sieve drum heating device 4, a cooling drum 5attached thereto, and a take-up means 6. The elements 1, 2, 6, and alsothe spray bonding device 7 illustrated between the needling machine 2and the sieve drum device 4 do not form a part of this invention, butonly serve to explain the operation of the sieve drum device of thepresent invention. The fleece laying device 1 imposes its productionspeed on all units. Such a device can operate, due to its constructionand due to the delivery speed of the fleece from the textile preparingmachines connected in front thereof, only at a relatively low speed of,for example lO-l5 meters per minute, so that a sieve drum 8, onlyone-half of which is surrounded by the fleece, is fully sufficient as aheating unit for the fleece. The area not covered by the material 3 isshielded from the suction draft of the fan 10 by means of an innerbaffle or cover 9. The fan is disposed at the front face of the sievedrum 8 in a fan chamber separated from the treatment chamber (whicharrangement is similar to that disclosed in US. Pat. No. 3,619,322). Thefan blows the treatment medium from the front face downwardly in thedirection toward the heating units 11 located in the bottom portion ofthe housing. After heating, the gas medium passes, for flowequalization, through the perforated metal plate 12 into the uppertreatment chamber and thus to the fleece 3. The fleece is passed throughby the gaseous treatment medium due to the suction draft and is thusheated to the treatment temperature in a minimum amount of time.

The construction of the sieve drum heating device 4 has two fresh airintake openings for controlling the fresh air required for the treatmentand for the timely fixation of the condition attained by the heatingstep; one opening 13 is arranged at the inlet, and another opening 14 isarranged at the outlet. Both openings are adjustable in their openingcross sections by means of flaps l5 and 16, respectively. Incorrespondence with the taken in amount of fresh air, a certain quantityof gas will be discharged from the apparatus through the waste air pipe17 in the upper portion of the treatment chamber.

A cooled pair of pressure rolls 18 is disposed directly at the outlet ofthe housing. The rolls are driven, and the contact pressure of the upperroll is made variable on the lower roll by means of a pneumatic orhydraulic device 19. Also, the upper roll can be lifted off the lowerroll by unit 19.

Once a textured synthetic textile material has been prepared for thetreatment by the laying unit 1 and has been formed by means of theneedling machine 2, the fresh air intake opening 13 is closed and theoutlet opening 14 is opened. Simultaneously, the upper roll of the pairof pressure rolls 18 is lifted and disengaged from its drive. By thefresh air taken in at the outlet, the heated and partially tacky textilematerial is thus rapidly cooled and fixed or set, and consequently acontacting of the face side of the textured material with the lower rollof the pair of pressure rolls 18 has no longer any effect on the surfacecharacteristic of the material, and the same holds true for the finaltreatment on the cooling drum 5 under a suction draft.

In addition to these measures for controlling the quality of thematerial, it is also possible to vary the treatment time, with the drumdiameter and the rotational speed of the drum remaining the same, bymeans of the fan speed which is controllable in its effect. Fur--thermore, by the additionally provided inner baffle or cover 20,arranged to be telescopically displaceable with respect to the internalcover 9, it is likewise possible to vary the duration of treatment bythe treatment medium. Also, this inner cover should be adjustable in itsair permeability, for example, by means of variable, louver-typeapertures, which makes it possible to vary the extent of the suctiondraft effective at the inlet as desired. Thus, for example, materialsprayed with a binder liquid or liquor by means of the device 7 can alsobe treated on this sieve drum unit without disadvantage. In place of thespraying device 7, a padder or the like device for applying a treatingliquid such as the binder liquid to the fleece can also be provided.Fleeces of a high binder bath absorption of, for example, 300-500% canbe dried and bonded. In this connection, a reduced suction draft isimportant in the first drying zone, so that the binder liquor is notremoved by too high a suction draft. With further drying on the drum,the binder liquor is thickened, so that there is no danger of removingthis liquor even in case of higher suction drafts.

The louver can be formed, according to this invention, by twosuperimposed, perforated plates, one of which is displaceable. By theshifting of one of the plates, the holes can be covered entirely orpartially and thus the opening cross section through the louver can bevaried.

The sieve drum device can also be used, by a special mode of operation,for the production of a material which, with a uniformly distributedhinder or bonding fiber content over its cross section, has a hardhandle only on one side and, on the other side, a textile-like handle.For this purpose, the material is heated on the sieve drum 8 only up toa few degrees below the bonding temperature of the binder fiber materialand, after leaving the unit 4, heated on its backside to the bondingtemperature by the infrared heating device 21. A press can followthereafter. Thus, the face side remains unbonded as a result thereof,but the product in total has sufficient resistance to withstand therequired stresses.

While the novel embodiments of the invention have been described, itwill be understood that various omissions, modifications and changes inthese principles may be made by one skilled in the art without departingfrom the spirit and scope of the invention.

What is claimed is:

1. In a sieve drum device for the bonding of fleece, needled felt, felt,and similar textile material products by means of thermoplastic binderfibers contained in the textile material which are made to become tackyor to melt by a shock-like heat treatment, wherein the device includes ahousing with a first sieve drum means subjected to a suction draft androtatably mounted in the housing for heat-treatment purposes, followedby a pair of pressure rolls, which rolls are followed by a second sievedrum means subjected to a suction draft for the cooling of the textilematerial, the improvement which is characterized in that the pair ofrolls is disposed directly at an outlet of the first sieve drum housingfor said textile material; the rolls can be pressed against each otherunder a variable pressure, by hydraulically or pneumatically operatedmeans; and the first sieve drum means is associated, across an operatingwidth of said first sieve drum means at a portion covered by the textilematerial with a first and a second fresh air intake opening means, saidfirst air intake opening means being located at an inlet in said housingfor said textile material and said second fresh air intake opening meansbeing located at a zone adjacent to the pair of rolls, said fresh airintake opening means each being adjustable in its opening cross sectionand each being closable independently of the other.

2. The device of claim 1, in which the pair of rolls are driven.

3. The device of claim 1, in which first means are provided for liftingthe top roll of the pair of rolls off the bottom roll, and other meansare provided for pressing the top roll against the bottom roll inopposition to the force applied by said first means.

4. The device of claim 1, in which the suction draft is variablyadjustable by means of a fan associated with the sieve drum.

5. The device of claim 1, in which a first inner sieve drum cover meansis provided, in said first sieve drum means in the zone not covered bythe textile material to be treated, and second inner sieve drum covermeans adjustable in its degree of effectiveness is furthermore provided,in said first sieve drum means in the region of the inlet in the zonecovered by the material.

6. The device of claim 5, in which the second inner cover means isformed so that it is telescopically displaceable over the first covermeans.

7. The device of claim 5, in which the second inner cover means isfashioned to be air-permeable.

8. The device of claim 1, in which said pressure rolls are arranged whenin an operative position to press against each other under said variablepressure and are arranged when in an inoperative position to beseparated from each other.

9. The device of claim 8, in which said fresh air intake opening meansis adjusted in an open position when said pressure rolls are in theinoperative position. I=

1. In a sieve drum device for the bonding of fleece, needled felt, felt,and similar textile material products by means of thermoplastic binderfibers contained in the textile material which are made to become tackyor to melt by a shock-like heat treatment, wherein the device includes ahousing with a first sieve drum means subjected to a suction draft androtatably mounted in the housing for heat-treatment purposes, followedby a pair of pressure rolls, which rolls are followed by a second sievedrum means subjected to a suction draft for the cooling of the textilematerial, the improvement which is characterized in that the pair ofrolls is disposed directly at an outlet of the first sieve drum housingfor said textile material; the rolls can be pressed against each otherunder a variable pressure, by hydraulically or pneumatically operatedmeans; and the first sieve drum means is associated, across an operatingwidth of said first sieve drum means at a portion covered by the textilematerial with a first and a second fresh air intake opening means, saidfirst air intake opening means being located at an inlet in said housingfor said textile material and said second fresh air intake opening meansbeing located at a zone adjacent to the pair of rolls, said fresh airintake opening means each being adjustable in its opening cross sectionand each being closable independently of the other.
 2. The device ofclaim 1, in which the pair of rolls are driven.
 3. The device of claim1, in which first means are provided for lifting the top roll of thepair of rolls off the bottom roll, and other means are provided forpressing the top roll against the bottom roll in opposition to the forceapplied by said first means.
 4. The device of claim 1, in which thesuction draft is variably adjustable by means of a fan associated withthe sieve drum.
 5. The device of claim 1, in which a first inner sievedrum cover means is provided, in said first sieve drum means in the zonenot covered by the textile material to be treated, and second innersieve drum cover means adjustable in its degree of effectiveness isfurthermore provided, in said first sieve drum means in the region ofthe inlet in the zone covered bY the material.
 6. The device of claim 5,in which the second inner cover means is formed so that it istelescopically displaceable over the first cover means.
 7. The device ofclaim 5, in which the second inner cover means is fashioned to beair-permeable.
 8. The device of claim 1, in which said pressure rollsare arranged when in an operative position to press against each otherunder said variable pressure and are arranged when in an inoperativeposition to be separated from each other.
 9. The device of claim 8, inwhich said fresh air intake opening means is adjusted in an openposition when said pressure rolls are in the inoperative position.